Effects of sodium diformate on growth performance, gut microflora, digestive enzymes and innate immunological parameters of Asian sea bass (
            Lates calcarifer
            ) juveniles

Abstract Salinity is one of the most critical environmental parameters regarding fish physiology, modifying food intake and growth performance in many fish species. The present study has investigated the effects of different salinity levels on growth performance, feeding and survival of Asian seabass Lates calcarifer juveniles. Asian seabass juveniles were reared at 0, 5, 22, 36, and 42 ppt salinity. One five hundred ninety-eight fish individuals with an average weight 1.2 ± 0.11 g were randomly distributed (166 fish/Tank) in 5 concrete tanks (30×6×4 feet) each; length × width × depth) and volume 19,122 L, for total forty days. Initially feeding rate of 6% biomass per day with 42% crude protein-containing diets daily. The feeding rate adjusted according to fish biomass every week. The results showed that salinity level had a significant effect on the weight gain, average daily weight gain, specific growth rate, feed conversion ratio, survival rate, total biomass and health indices (p < 0.05). The highest WG (39.11±1.49 g), ADWG, (1.00±0.12 g), SGR (8.74±0.03 % d-1) and lowest FCR (0.96±0.20) observed with T3 (22 ppt salinity) treatment, which was significantly higher compared to other treatment groups (p < 0.05). Among the health indices, the highest hepatosomatic index and viscerosomatic index found with 22 ppt salinity treatment, which was also significantly higher than the other treatment groups (p < 0.05). No significant differences were found among the treatments in terms of survival rate (p > 0.05), but the maximum survival rate (98.89±0.0 %) in T3 (22 ppt) and T2 (5 ppt). The maximum level of crude proteins (19.99±1.4%) was found in the whole-body biochemical composition (% of wet weight) of Asian sea bass juveniles in T3 treatment group reared at 22 ppt salinity. The second-order polynomial regression showed that 20 ppt salinity is optimum for the best growth of Asian sea bass. Thus, our present work would provide valuable information to the fish farmers for culturing the sea bass as well as its management along the inland and coastline of Pakistan.

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Effects of dietary inclusion of Spirulina meal on growth and hematological parameters of cultured Asian sea bass, Lates calcarifer

Borneo Journal of Marine Science and Aquaculture (BJoMSA) ◽

10.51200/bjomsa.v1i0.984 ◽

2017 ◽

Author(s):

Chin Yong Tan ◽

German Bueno Galaz ◽

Rossita Shapawi

Keyword(s):

Growth Performance ◽

Fish Meal ◽

Hematological Parameters ◽

Control Diet ◽

Sea Bass ◽

Whole Body ◽

Fish Stock ◽

Feed Conversion ◽

Lates Calcarifer ◽

Asian Sea Bass

This study was conducted to investigate the effects of dietary inclusion of Spirulina platensis on growth performance and hematological parameters of juvenile Asian sea bass (Lates calcarifer) reared in a freshwater culture system. Five experimental diets were prepared by replacing fish meal protein with the microalga at replacement levels of 5% (SP5), 10% (SP10), 20% (SP20) and 30% (SP30), and the substitution effect was compared with a control diet (Con) in which fish meal was the sole protein. Fish were stocked in net cages placed in a 150-ton tank with a stocking density of 20 fish per cage. After 8 weeks of feeding trial, the fish did not show any significant differences in growth performance but numerically higher weight gain and specific growth rate were achieved in the fish stock fed diet SP10 compared to other treatments. Feed conversion ratio and survival rate of fish were significantly affected by the inclusion of Spirulina in the diets. Except for crude ash content, whole-body proximate composition of the experimental fish was also significantly influenced by the diets. Regarding the effects of diets on blood parameters, only hematocrit, hemaglobin, HDL-c and AST were significantly affected by the inclusion of Spirulina in the diets. This study demonstrated that Spirulina could replace up to 10% of FM protein in practical diets of juvenile Asian sea bass without negative effects on growth performance. However, replacement of fish meal with Spirulina meal at 5% might be considered for commercial use considering a significant decrease in survival above this value.

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